Seminiferous tubules produce and store sperm

Sertoli cells (in the tubules) provide nutrition for the development of sperm

This process begins with spermatogonium on the outer wall of the tubules; they move toward the center during development as primary spermatocytes, then divide to form secondary spermatocytes, and divide again into spermatids

Spermatids form the compact head covered by an acrosome that contains enzymes to penetrate the egg

Spermatids form the compact head covered by an acrosome that contains enzymes to penetrate the egg

The midpiece is formed and serves as the energy source

The flagellum propels the mature sperm

Sperm production takes 72 days, but is constant and each male produces about 300 million sperm a day

Figure 6.5 Spermatogenesis is continually taking place with various levels of sperm development throughout the testis.

Figure 6.5 Spermatogenesis is continually taking place with various levels of sperm development throughout the testis.

Immature sperm travel from the tubules to the epididymis; organ that rests atop the testicle

Immature sperm travel from the tubules to the epididymis; organ that rests atop the testicle

Old and faulty sperm are reabsorbed here

They mature in 10-14 days in the epididymis

Upon maturity they are transferred to the vas deferens for storage

Erection

Erection

Blood vessels expand and increase blood in penis

Veins that normally carry blood out are compressed, leading to engorgement of penis

Secretions from Cowper’s glands appear at tip

Ejaculation – physiological process where seminal fluid is powerfully expelled from the penis

Ejaculation – physiological process where seminal fluid is powerfully expelled from the penis

Controversy over hormone treatments

Diseases of the male reproductive organs

Diseases of the male reproductive organs

Other conditions that affect the male reproductive organs

Cancer of the male reproductive organs

Cryptorchidism – testes do not descend into the scrotum; surgery necessary to correct

Cryptorchidism – testes do not descend into the scrotum; surgery necessary to correct

Diseases of the male reproductive organs

Diseases of the male reproductive organs

Other conditions that affect the male reproductive organs

Cancer of the male reproductive organs

Cryptorchidism – testes do not descend into the scrotum; surgery necessary to correct

Cryptorchidism – testes do not descend into the scrotum; surgery necessary to correct

Figure 6.7 Although the testicles of a fetus begin high in the abdomen, they must descend into the scrotum during fetal development. If they do not, the male may become infertile.

Testicular torsion – testis is twisted on its spermatic cord; many causes (sex, exercise, sleep); symptoms are pain and swelling; immediate surgery is required to maintain the testicle

Testicular torsion – testis is twisted on its spermatic cord; many causes (sex, exercise, sleep); symptoms are pain and swelling; immediate surgery is required to maintain the testicle

Figure 6.8 Testicular torsion can occur after exercise, sexual intercourse, and even while sleeping.

Priapism – persistent, painful erection not related to sexual excitement; blood is trapped in erectile tissue; common causes are drug use and unknown; treatment is cessation of drug use and, possibly, surgery

Priapism – persistent, painful erection not related to sexual excitement; blood is trapped in erectile tissue; common causes are drug use and unknown; treatment is cessation of drug use and, possibly, surgery

Peyronie’s disease – painful curvature of the penis making penetration impossible; cause is unknown; may disappear within 2 years, or require drugs or surgery

Anabolic-androgenic steroid use – synthetic testosterone can increase muscle mass and endurance; there are also numerous physical, psychological, and emotional side effects, including erectile problems

Anabolic-androgenic steroid use – synthetic testosterone can increase muscle mass and endurance; there are also numerous physical, psychological, and emotional side effects, including erectile problems

Inguinal hernia – intestine goes through an abdominal opening into the scrotum, creating a bulge; can be due to heavy lifting and straining; surgery may be required

Inguinal hernia – intestine goes through an abdominal opening into the scrotum, creating a bulge; can be due to heavy lifting and straining; surgery may be required

Hydrocele – fluid accrues & forms a scrotal mass

Testicular

Testicular

Penile

Prostate

Most common cancer in men 15-44 years

Most common cancer in men 15-44 years

Few early symptoms, early detection important; testicular self-exam

Symptoms: painless mass or hardness in the testes; pain or increase in size of the testes, lower back pain, gynecomastia, shortness of breath, urethral obstruction

High cure rate: radiation, chemotherapy, removal of testicle

Lesions on the penis may be benign or malignant and are usually treatable; may also be a STI

Lesions on the penis may be benign or malignant and are usually treatable; may also be a STI